Battery Cell, Battery and Electrical Apparatus

The present application is a continuation of International Application No. PCT/CN2024/080760, filed on Mar. 8, 2024, which claims priority to Chinese Patent Application No. 202310529161.9 filed with the China National Intellectual Property Administration on May 11, 2023 and entitled “BATTERY CELL, BATTERY AND ELECTRICAL APPARATUS”, the entire contents of both of which are incorporated herein by reference.

The present application relates to the field of batteries, in particular to a battery cell, a battery and an electrical apparatus.

Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. In this case, due to the advantages of energy conservation and environment protection, electric vehicles have become an important part of the sustainable development of the automobile industry. The battery technology is an important factor related to the development of electric vehicles.

With the development of the battery technology, various battery performances are constantly improving. During the use process of a battery, the reliability of the electrical performance of the battery is an important factor for measuring the quality of the battery. Therefore, how to improve the reliability of batteries is still a problem to be solved.

Embodiments of the present application provide a battery cell, a battery and an electrical apparatus, which can improve the reliability of batteries.

According to a first aspect, a battery cell is provided, including: an electrode terminal; a first wall, the first wall being provided with an electrode lead-out hole, and the electrode terminal and the electrode lead-out hole being arranged opposite to each other; and a sealing member, the sealing member being arranged around the electrode lead-out hole, the sealing member including an extension portion, the extension portion being at least partially arranged between the first wall and the electrode terminal, the extension portion being provided with one of a first protrusion and a first groove, the first wall being provided with the other one of the first protrusion and the first groove, and the first protrusion and the first groove being matched with each other.

By arranging the mutually matched protrusion and groove on the sealing member and the first wall, the sealing member and the first wall may be matched more closely to improve the sealing degree between the sealing member and the first wall and reduce the possibility of the sealing member falling off, thereby improving the reliability of the battery cell.

In some embodiments, the surface of the first wall facing the extension portion has the first groove, and the surface of the extension portion facing the first wall has the first protrusion.

By arranging the first groove on the first wall and arranging the first protrusion matched with the first groove on the sealing member, in a case that the first wall is subjected to a pressure perpendicular to the first wall, a side wall of the first groove can limit the relative sliding between the first protrusion and the first groove, which is conducive to reducing the possibility of the sealing member falling off from the first wall, thereby improving the sealing degree of the sealing member to the first wall and improving the reliability of the battery cell.

In some embodiments, the first protrusion is located at the outer edge of the extension portion.

In a case that the first wall is subjected to an external force, the deformation of the region where the outer edge of the sealing member is located is smaller, and the first protrusion is not easy to slip out of the first groove, thereby reducing the possibility of the sealing member detaching from the first wall, improving the sealing degree of the sealing member to the first wall, and improving the reliability of the battery cell.

In some embodiments, the extension portion has a plurality of first protrusions, and the plurality of first protrusions are arranged at intervals along the radial direction of the electrode lead-out hole.

The plurality of first protrusions can limit the relative sliding between the first protrusions and the first grooves at a plurality of positions, thereby further reducing the possibility of the sealing member falling off from the first wall.

In some embodiments, the distance between the surface where the opening of the first groove is located and the surface where the bottom wall of the first groove is located is A2, the distance between the surface where the opening of the first groove is located and the surface of the first wall away from the extension portion is A, and A2 and A satisfy: A2/A≤95%, and/or A−A2≥0.2 mm.

Satisfying the above range can make the first wall have higher strength and reduce the possibility of the first wall being broken by an external force.

In some embodiments, the size of the first protrusion in the radial direction of the electrode lead-out hole is T1, the size of the first groove in the radial direction of the electrode lead-out hole is A1, and A1 and T1 satisfy: T1/A1≤98%, and/or A1−T1≥0.1 mm.

Satisfying the above range is conducive to improving the production efficiency and qualified rate of the battery cell.

In some embodiments, the size of the first protrusion in the thickness direction of the first wall is T2, the maximum size of the first groove in the thickness direction of the first wall is A2, and T2 and A2 satisfy 0<T2/A2≤100%.

Satisfying the above range can achieve better sealing between the first wall and the electrode terminal, which is conducive to improving the reliability of the battery cell.

In some embodiments, the size of the first protrusion in an uncompressed state in the thickness direction of the first wall is T3, the maximum size of the first groove in the thickness direction of the first wall is A2, and T3 and A2 satisfy 30%<T3/A2≤150%.

Satisfying the above range allows the sealing member to provide good sealing performance for the battery cell while limiting the sliding of the sealing member in a case that the first wall is deformed by a force, thereby reducing the possibility of the sealing member falling off from the first wall, which is conducive to improving the reliability of the battery.

In some embodiments, T3 and A2 satisfy 85%<T2/A2≤100%.

This can improve the limiting effect on the first protrusion on the relative sliding of the sealing member, and can also achieve a better sealing effect.

In some embodiments, the surface of the first wall facing the extension portion is provided with a second protrusion, the second protrusion is arranged around the electrode lead-out hole, the extension portion is provided with a second groove, and the second protrusion is matched with the second groove.

By arranging the second protrusion and second groove matched with each other, the sealing member may be better positioned during the assembly process with the first wall, thereby reducing the possibility of assembly failure caused by misalignment between the sealing member and the first wall.

In some embodiments, the surface of the first wall away from the extension portion is provided with a third protrusion corresponding to the first groove.

The third protrusion may increase the thickness of the first wall in the region where the first groove is located, improve the strength of the first wall, and reduce the possibility of the first wall being broken in a thinner region due to an external force, thereby improving the reliability of the battery cell.

In some embodiments, the size of the third protrusion in the radial direction of the electrode lead-out hole is C1, the size of the first groove in the radial direction of the electrode lead-out hole is A1, the length of the first wall is L, and A1, C1 and L satisfy: A1≤C1≤50 mm, and/or C1/L≤50%.

Satisfying the above range can improve the strength of the first wall and reduce the production cost.

In some embodiments, the joint between the third protrusion and the first wall is provided with a rounded corner and/or a chamfered corner.

The rounded corner and/or the chamfered corner may reduce the possibility of stress concentration in a transition region between the third protrusion and the first wall, which is conducive to improving the strength of the first wall, so that the first wall is not easily broken when subjected to an external force.

In some embodiments, the joint between the third protrusion and the first wall is provided with a first rounded corner and/or a second rounded corner, and in the radial direction of the electrode lead-out hole, the first rounded corner is close to the electrode lead-out hole, and the second rounded corner is far away from the electrode lead-out hole.

The first rounded corner and/or the second rounded corner may reduce the stress concentration at corresponding positions, so that the first wall is not easily broken in the transition region between the third protrusion and the first wall when subjected to an external force, which is conducive to improving the reliability of the first wall.

In some embodiments, the radius of the first rounded corner and/or the second rounded corner is half of the size of the third protrusion in the thickness direction of the first wall.

This may reduce the stress concentration at the corresponding corner positions, which is conducive to improving the strength of the first wall.

In some embodiments, the joint between the third protrusion and the first wall is provided with a first chamfered corner and/or a second chamfered corner, and in the radial direction of the electrode lead-out hole, the first chamfered corner is close to the electrode lead-out hole, and the second chamfered corner is far away from the electrode lead-out hole.

The first chamfered corner and/or the second chamfered corner may reduce the stress concentration at corresponding positions of transition between the third protrusion and the first wall, so that the first wall is not easily broken in the transition region between the third protrusion and the first wall when subjected to an external force, which is conducive to improving the reliability of the first wall.

In some embodiments, the chamfered corner size of the first chamfered corner and/or the second chamfered corner along the thickness direction of the first wall is C4, the size of the third protrusion in the thickness direction of the first wall is C2, and C2 and C4 satisfy 0.1 mm≤C4≤C2.

This may reduce the stress concentration at the position of the first chamfered corner and/or the second chamfered corner.

In some embodiments, the third protrusion is provided with a third rounded corner and/or a third chamfered corner at an end away from the extension portion.

This may reduce the stress concentration at the corner of the third protrusion and reduce the possibility of deformation and cracking of the third protrusion, thereby being conducive to improving the strength of the first wall.

In some embodiments, the size of the third protrusion in the radial direction of the electrode lead-out hole is C1, and the size in the thickness direction of the first wall is C2; the chamfered corner size of the third chamfered corner in the radial direction of the electrode lead-out hole is C7, and the chamfered corner size along the thickness direction of the first wall is C8; and C1, C2, C7 and C8 satisfy: 0.1 mm≤C7≤C2, and/or 0.1 mm≤C8≤0.45C1.

This may reduce the stress concentration at the position of the third chamfered corner, and can also improve the strength of the first wall.

In some embodiments, the joint between the bottom wall and the side wall of the first groove is provided with a rounded corner.

The rounded corner transition between the bottom wall and the side wall of the first groove may reduce the stress concentration that may be generated at the corner of the first groove, and may also reduce the stress concentration generated after the sealing member is compressed in the first groove, so as to improve the strength of the first wall at the first groove, thereby being conducive to improving the reliability of the battery cell.

In some embodiments, the surface of the first wall facing the extension portion has the first protrusion, the surface of the extension portion facing the first wall has the first groove, and the first groove is located at the outer edge of the sealing member.

The structure of arranging the first groove on the sealing member and arranging the first protrusion on the first wall can limit the relative sliding of the sealing member and the first wall without reducing the thickness of the first wall. This can not only improve the strength of the first wall, but also help reduce the possibility of the sealing member falling off from the first wall, thereby improving the sealing degree of the sealing member to the first wall and improving the reliability of the battery cell.

In some embodiments, a fixing member is arranged around the electrode terminal, and the fixing member is configured to fix the electrode terminal and the first wall.

By arranging the fixing member around the electrode terminal, on the one hand, the electrode terminal may be fixed to the first wall, and on the other hand, it is conducive to the insulation between the electrode terminal and the first wall, thereby reducing the possibility of short circuit of the battery cell.

In some embodiments, the fixing member includes an insulating portion, the insulating portion surrounds the electrode terminal, and a part of the sealing member provided with the first protrusion or the first groove is located between the insulating portion and the first wall.